Malaysia has "nothing to hide" in the search for the missing flight MH370, the country's transport minister has insisted.

Hishammudin Hussein said the situation was 'unprecedented', and nothing had been done to jeopardise the effort to find the aircraft.

And he dismissed reports that the plane had continued to fly for four hours after its final transmission early on Saturday morning.

Images were released by "mistake" and did not show debris from MH370

:: Watch Sky News to see a special report on the missing Malaysian Airlines plane at 4.30pm.

Malaysia Airlines has also admitted it is no further forward in finding out what happened to the plane, and its disappearance remained a "complete mystery".

Video:Airline Boss Criticises Jet Rumours

Satellite images appearing to show possible debris were investigated by search aircraft, but officials later revealed these had been released by mistake and did not show any plane parts.

The pictures had briefly raised hopes of an end to the mystery surrounding the fate of flight MH370, which left Kuala Lumpur bound for Beijing six days ago with 239 people on board.

Speaking in Kuala Lumpur the Malaysian transport minister said: "This is a crisis situation. It's a very complex operation.

"Our focus has been finding the aircraft. We have spared no expense and no effort.

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Gallery: Malaysia Mystery: Search For Missing Plane

Malaysian Air Force close the door of a search and rescue mission flight in Kuala Lumpur, Malaysia.

"We have not done anything that would jeopardise this search effort. Malaysia has nothing to hide."

He added: "I would like to refer to news reports suggesting that the aircraft may have continued flying for some time after the last contact.

"Those reports are inaccurate. The last transmission from the aircraft was at 01:07 which indicated that everything was normal."

The minister also denied the homes of crew member's had been searched by police.

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Meanwhile, Hugh Dunleavy, commercial director of Malaysia Airlines, told Sky News they were no closer to establishing what might have happened to the plane.

He said: "We have had all our search and rescue assets from almost a dozen countries searching the areas both in the South China Sea and the west-side of Malaysia, but so far we have found no trace of the missing aircraft.

Mr Dunleavy added: "We are definitely being 100% transparent. We have our own crew members onboard.

"There's absolutely no reason why we would be hiding any information, we certainly are not doing so.

Video:No Wreckage At Satellite Pic Site

"We have been contacting and working with all of the appropriate authorities in every jurisdiction to help find this aircraft."

He went on: "We don't know where that aircraft is, it's a complete mystery at this stage.

"Until we find it, I think you will find many of the people are going to be increasingly frustrated as time goes by.

"Most importantly, we are more concerned about the needs of the family members who are trying to find out what happened to their loved-ones."

Video:Flight MH370: The Story So Far

There are now 43 ships and 40 aircraft engaged in the search effort, which has been widened to cover 27,000 square nautical miles.

The last words from the cockpit of the Boeing 777 have also been released.

The pilot replied "Okay, received, goodnight" when Malaysian air traffic controllers signed off and told the plane it was entering Vietnam's airspace. Vietnamese controllers say they never heard from the aircraft.

There is mounting frustration and anger among relatives at the lack of progress in the hunt for the flight.

The majority of the passengers on board were Chinese, and impatience is growing there.

Premier Li Keqiang said: "This is an international and large-scale search operation involving many countries.

"The Chinese government has asked relevant parties to enhance coordination, investigate the cause, locate the missing Malaysia Airlines plane and properly handle all related matters."